May Day is coming. What plan do you have for it, Eric?

I’m going to Yunnan.  1  .

Really? Great. Are you going with your parents?

  2 .So I’m going with my mother. What about you?

 3 But my parents say it’s dangerous.

Then what are you doing?

A.   4  .

B.   Great. You can visit Cambridge University—my favorite university. But the weather there is changeable(多变).  5

单位重量的液体从水泵进口到出口所增加的能量，称为（）。

A.扬程

B.吸水扬程

C.压水扬程

D.实际扬程